AT&T (NYSE: T) raised a lot of hackles when it removed unlimited 3G data plans in favor of a tiered data traffic model. Sure, some people will save a couple of bucks a month, but do you really want to place limits on data usage just when Apple (Nasdaq: AAPL) and Google (Nasdaq: GOOG) are figuring out how to make bandwidth-hungry gadgets that we actually want to use?

Now British mobile operator O2 has followed suit. In conjunction with launching the iPhone 4, O2 is doing away with its own unlimited data plans, replaced by a layer cake of various limit levels. O2 is the pan-European arm of Telefonica (NYSE: TEF), a global telecom with 273 million subscribers worldwide. AT&T and Verizon (NYSE: VZ) look like toddlers next to this giant, and yet AT&T’s actions seem to have pan-Atlantic implications. Europe’s no stranger to tiered pricing models, and it looks like the recent trend toward metered data will only continue.

So, the ball has been set in motion, and I wouldn't be surprised to see this storm in a teacup escalating into a full-blown hurricane. Some operators will take the AT&T/O2 route and restrict mobile data usage, ostensibly to save money for their customers but really to give themselves more time to roll out expensive network upgrades. Unlimited data plans have been known to induce traffic congestion, and this is the cheaper and easier way for telecoms to back out of that trap. I'm keeping an eye on Verizon Wireless, here, especially after the company’s recent statements indicating a preference for tiered pricing on 4G data.

Others should pounce on the opportunity to market themselves as unlimited data providers -- probably underdogs like Sprint Nextel (NYSE: S) and T-Mobile in the U.S., who could use a secret weapon against the Verizon-AT&T hegemony at the top.

In the end, the consumer will decide the winner of this war. The key question is, will they (we?) stand up and demand full service, or just turn the other cheek to save a couple of bucks? I sure hope the first answer is the correct one. We shall see in a year or so. Invest according to your prognostications today. And please share your thought process in the comments box below.